From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Gleixner Subject: Re: [PATCH 2/2] x86: of: define irq functions to allow drivers/of/* to build on x86 Date: Tue, 21 Sep 2010 11:43:47 +0200 (CEST) Message-ID: References: <20100910060151.6613e9c3@debxo> <20100910172538.GC11284@angua.secretlab.ca> <20100910181458.GA7243@elte.hu> <20100910182135.GG11284@angua.secretlab.ca> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Return-path: In-Reply-To: <20100910182135.GG11284@angua.secretlab.ca> Sender: linux-kernel-owner@vger.kernel.org To: Grant Likely Cc: Ingo Molnar , Andres Salomon , devicetree-discuss@lists.ozlabs.org, x86@kernel.org, mingo@redhat.com, hpa@zytor.com, Mitch Bradley , linux-kernel@vger.kernel.org, Stephen Neuendorffer List-Id: devicetree@vger.kernel.org On Fri, 10 Sep 2010, Grant Likely wrote: > On Fri, Sep 10, 2010 at 08:14:58PM +0200, Ingo Molnar wrote: > > > > * Grant Likely wrote: > > > > > On Fri, Sep 10, 2010 at 06:01:51AM -0700, Andres Salomon wrote: > > > > > > > > - Define a stub irq_create_of_mapping for x86 as a stop-gap solution until > > > > drivers/of/irq is further along. > > > > - Define irq_dispose_mapping for x86 to appease of_i2c.c > > > > > > > > Signed-off-by: Andres Salomon > > > > > > Applied to my test-devicetree branch. I'll need an ack from the x86 > > > maintainers before I put it into my -next branch. > > > > The purpose of the patch is not clear to me. What does it do and why? > > It allows CONFIG_OF to be enabled on x86 without a build failure. > > > The changelog says it's a stopgap measure - what exactly is the long > > term plan and how long will it take? > > It is a stop gap because it performs a trivial direct map of an IRQ > number in the device tree data structure to a Linux irq number. This > works for a single IRQ controller, but falls apart when cascaded > controller are described in the device tree. The long term plan is to > have the drivers/of/ code handling the mapping intelligently like > powerpc currently does. Sounds good. We need this for other embedded x86 platforms as well and I was looking into the powerpc code before and wondered how we can make that generic. The question is whether this should be tied into drivers/of/irq or just provided as an OF independent generic facility in kernel/irq. Thanks, tglx